Fairing Assembly for at Least One Axle of a Commercial Vehicle

ABSTRACT

A fairing assembly for a commercial vehicle includes a forward fairing configured to be disposed such that the forward fairing begins inboard of an outer tire tread edge of a tire of a forward drive wheel and progresses outwards to end outboard of a wall of the tire of the forward drive wheel with respect to a longitudinal direction of the commercial vehicle. The fairing assembly further includes a rear fairing configured to be disposed such that the rear fairing begins inboard of an outer tire tread edge of a tire of a rear drive wheel and progresses outwards to end outboard of a wall of the tire of the rear drive wheel with respect to the longitudinal direction of the commercial vehicle, where the rear fairing has a concave cross-section in a transverse direction of the commercial vehicle.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/553,893, filed Aug. 25, 2017, which was the National Stage ofInternational Application No. PCT/EP2016/000313, filed Feb. 23, 2016,which claims priority from British Patent Application No. 1503330.1,filed Feb. 27, 2015, the entire disclosures of which are hereinexpressly incorporated by reference.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a fairing assembly for at least one axle of acommercial vehicle.

WO 2013/174410 A1 shows a wing-guiding device for a utility vehicle, thewing-guiding device having an air-guiding system which, to reduce theair resistance of the utility vehicle, has at least one air-guidingelement arranged on a rear end.

Moreover, WO 2004/062953 A2 shows a cab chassis fairing for a tractorunit of an articulated vehicle, the fairing comprising a substantiallyflat panel extending along a side of the tractor unit adjacent to theground, the panel having one or more openings for venting air frombeneath a trailer. Thus, it is known from the general prior art to usefairings for commercial vehicles to guide air in order to reduce thedrag of the vehicle.

It is an object of the present invention to provide a fairing assemblyfor at least one axle of a commercial vehicle, by means of which fairingassembly particularly advantageous aerodynamics of the vehicle can berealized.

The invention relates to a fairing assembly for at least one axle of acommercial vehicle. The fairing assembly comprises at least one forwardfairing configured to be arranged at least partially in front of a drivewheel of the axle with respect to the longitudinal direction of thevehicle. Moreover, the fairing assembly comprises at least one rearfairing configured to be arranged at least partially aft of the drivewheel. Each of the fairings comprises at least one first portion made ofa first material and at least one second portion adjoining the firstportion, wherein the second portion is made of a second materialdifferent from the first material. For example, the respective secondportion forms a soft extension or a soft panel extension of therespective fairing, the soft extension being softer than the firstportion. Using different materials for the respective portions allowsfor an increase in the effective surface area of the respective fairingforming an aerodynamic panel with little impact on the durability orstructural integrity of the whole fairing. For example, the secondmaterial is flexible or more flexible than the first material so thatborders of an effective aero shape of the fairing can be extended wellinto a collision zone. It has been shown that using two differentmaterials for the portions and thus the respective fairing allowsrealizing a particularly high aerodynamic performance of the respectivefairing so that, for example, the drag of the commercial vehicle can bekept particularly low. Hence, the commercial vehicle which is, forexample, a tractor can be driven particularly efficiently.

In a particularly advantageous embodiment of the invention the firstmaterial is a first plastic material. Thus, a particularly highaerodynamic performance of the fairing assembly and thus the commercialvehicle can be realized, wherein the weight of the fairing assembly canbe kept particularly low.

Preferably, the first plastic material is a semi-rigid material such asa thermoplastic elastomer based on olefin (TPO). Thus, the first portionmade of a semi-rigid material such as TPO or similar is designed tomaintain an aerodynamic shape under normal operating conditions butdeflect when impacted.

In a further advantageous embodiment of the invention the secondmaterial is a second plastic material so that a particularly highaerodynamic performance of the fairing assembly can be realized.

Preferably, the second plastic material is a semi-flexible material suchas an Ethylene-Propylene-Dien-Monomer (EPDM) or similar. For example,the second portion is designed to maintain an aerodynamic shape undermost operating conditions but deflect when impacted. Thus, by usingdifferent materials for the portions of the respective fairing therespective portions can be adapted to their respective functions in aneed-based manner.

In a particularly advantageous embodiment of the invention therespective first portion has a higher rigidity than the respectivesecond portion. In other words, the second portion is more flexible orsofter than the first portion so that the second portion can bend ordeflect when impacted without any damage of the respective fairing.Preferably, the durometer of the flexible second material is chosen tobe aerodynamically stable while providing sufficient impact absorptionto withstand frequent impacts with rigid objects. The flexible secondmaterial is very durable but might also be considered as a sacrificialpiece intended to be replaced as needed. Thereby, significant relativemotions between the first portion and the softer second portion canoccur without any damage of the respective fairing.

In a further advantageous embodiment the respective second portion formsa respective edge region of the respective fairing. Thus, air can beguided particularly advantageously. Moreover, the respective firstportion can be protected by the second portion. For example, the secondportion is reversibly mounted on the first portion. Thus, the secondportion can be mounted on and dismounted from the first portion in anon-destructive manner.

In order to realize a particularly high aerodynamic performance, in afurther embodiment of the invention the forward fairing extends in thelongitudinal direction of the vehicle from front to back outwardly withrespect to the transverse direction of the vehicle. Thereby, air can beguided in a particularly advantageous manner by the forward fairing.

Moreover, in a particularly advantageous embodiment of the invention,the rear fairing extends in the longitudinal direction of the vehiclefrom front to back outwardly with respect to the transverse direction ofthe vehicle. Thereby, air that would normally flow towards and around atrailer or a landing gear of the trailer coupled to the commercialvehicle which is, for example, configured as a tractor can be divertedparticularly advantageously.

The invention also relates to a commercial vehicle, in particular atractor configured to pull a trailer, the commercial vehicle having atleast one axle and at least one fairing assembly according to thepresent invention. Advantages and advantageous embodiments of thefairing assembly according to the present invention are to be regardedas advantages and advantageous embodiments of the commercial vehicleaccording to the present invention and vice versa.

Further advantages, features, and details of the invention derive fromthe following description of a preferred embodiment as well as from thedrawings. The features and feature combinations previously mentioned inthe description as well as the features and feature combinationsmentioned in the following description of the figures and/or shown inthe figures alone can be employed not only in the respectively indicatedcombination but also in other combination or taken alone without leavingthe scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view of a fairing assembly for a tandem axleof a commercial vehicle in the form of a tractor, the fairing assemblycomprising a forward fairing arranged between two drive axles of thetandem axle, and at least one rear fairing arranged behind the driveaxles;

FIG. 2 is a schematic top view of the fairing assembly;

FIG. 3 is a schematic sectional view of the fairing assembly along a cutline A-A shown in FIG. 1;

FIG. 4 is a further schematic sectional view of the fairing assemblyalong the cut line A-A;

FIG. 5 is a further schematic sectional view of the fairing assemblyalong a cut line B-B shown in FIG. 1;

FIG. 6 is a schematic detail view of an area A shown in FIG. 3;

FIG. 7 is a schematic detail view of an area B shown in FIG. 3; and

FIG. 8 a schematic sectional view of the fairing assembly along a cutline C-C shown in FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

In the figures the same elements or elements having the same functionsare indicated by the same reference signs.

FIG. 1 shows in a schematic side view a fairing assembly 10 for a tandemaxle 12 of a commercial vehicle in the form of a tractor configured topull a trailer which can be pivotably coupled to the tractor. The tandemaxle 12 comprises a first drive axle 14 and a second drive axle 16,wherein the first drive axle 14 is a forward drive axle and the seconddrive axle 16 is a rear drive axle since the drive axle 16 is arrangedbehind the drive axle 14 in the longitudinal direction of the vehicle.As can be seen from FIG. 2, the respective drive axles 14 and 16comprise respective lateral twin wheels 18 and 20, wherein the twinwheels 18 and 20 comprise respective wheels 22 and 24 being inboardwheels. The respective twin wheels 18 and 20 further comprise respectivewheels 26 and 28 being outward wheels. The wheels 26 and 28 are shown inFIG. 1, wherein the wheels 22, 24, 26 and 28 are respective drive wheelssince the commercial vehicle (tractor) can be driven by the drivewheels. As can be seen from FIG. 1, the respective wheels 22, 24, 26 and28 comprise respective tires 30 and respective rims 32 on which therespective tires 30 are mounted. In FIG. 1 a directional arrow 34illustrates the direction of forward movement of the commercial vehicle.

The fairing assembly 10 is used to realize particularly advantageousaerodynamics of the vehicle and comprises a lateral forward fairing 36arranged at least partially between the wheels 26 and 28. Thus, theforward fairing 36 is arranged in front of the drive wheel 28. Moreover,the fairing assembly 10 comprises at least one lateral rear fairing 38arranged at least partially aft of the rear drive wheel 28. The forwardfairing 36 comprises a first portion 40 and second portions 42 and 44adjoining the first portion 40. Moreover, the rear fairing 38 comprisesa first portion 46 and a second portion 48 adjoining the first portion46. The respective first portions 40 and 46 are made of first materialsrespectively. The first portion 40 is a center aero panel, wherein thefirst portion 46 is an aft aero panel.

The respective second portion 42, 44 and 46 are made of second materialsrespectively, wherein the respective second material is different fromthe respective first material. For example, the respective firstmaterial is a semi-rigid material such as TPO (thermoplastic elastomerbased on olefin) or similar and designed to maintain an aerodynamicshape under normal operating conditions but deflect when impacted,wherein impact events in respective areas of the first portions 40 and46 will be few. The respective second material is a semi-flexiblematerial such as EPDM (Ethylene-Propylene-Dien-Monomer) or similar sothat the second material and thus the respective second portions 42, 44and 48 are more flexible or softer than the respective first portions 40and 46. The respective second portions 42, 44 and 48 are designed tomaintain an aerodynamic shape under most operating conditions butdeflect when impacted. Impact events in respective areas in which therespective second portions 42, 44 and 48 are arranged will be frequent.Using a different material for the second portions 42, 44 and 48 allowsfor an increase in the effective surface area of the respectiveaerodynamic panels in the form of the fairings 36 and 38 with littleimpact on the durability or structural integrity of the whole panels.

As can be seen from FIG. 1, the second portion 42 forms a center aeropanel upper extension and an edge region of the fairing 36. Moreover,the second portion 44 forms a center aero panel lower extension and afurther edge region of the fairing 36. Thus, the second portion 42adjoins the first portion 40 in the vertical direction of the vehicletowards the top, wherein the second portion 44 adjoins the first portion40 in the vertical direction of the vehicle towards the bottom.Moreover, the fairings 36 and 38 are arranged at a distance from eachother in the longitudinal direction of the vehicle. The second portion48 is an aft aero panel upper extension which adjoins the first portion46 in the vertical direction of the vehicle towards the top and towardsthe bottom and in the longitudinal direction of the vehicle towards theback.

Furthermore, respective tire clearance gaps are indicated by 50 inFIG. 1. As can be seen from FIG. 1, the design of the fairing assembly10 provides minimal panel-to-tire gaps (tire clearance gaps 50) whichprevent tire-to-panel contact under normal articulation of a suspensionof the respective drive axle 14 and 16. Assembly tolerances and tiresize variances are also considered. Since the respective fairings 36 and38 are used to cover respective portions of the commercial vehicle andguide air, the respective fairings 36 and 38 are also referred to aspanels or aero panels.

FIG. 2 shows the fairing assembly 10 in a schematic top view. As can beseen from FIG. 2, respective panel supports 52 and 54 are used to mountthe panels (fairings 36 and 38) on, for example, a frame of thecommercial vehicle. FIG. 3 shows the fairings 36 and 38 in a schematicsectional view. As can be seen from FIGS. 3 and 4 the forward fairing 36extends in the longitudinal direction of the vehicle from front to back,i.e., from the wheel 26 to the wheel 28 and outwardly with respect tothe transverse direction of the vehicle. This means the fairing 36 doesnot extend parallel to the longitudinal direction of the vehicle butangularly thereto. Moreover, the rear fairing 38 extends in thelongitudinal direction of the vehicle from front to back, i.e., awayfrom the drive wheel 28 and outwardly with respect to the transversedirection of the vehicle.

In FIG. 4, directional arrows 56 illustrate a wind direction at yaw. Theaerodynamic features of the fairing assembly 10 are most effective whenthe wind direction is not parallel to the vehicle frame or thelongitudinal direction of the vehicle. 0 to 9 degrees of yaw is commonunder normal operating conditions. The wind or air flowing against thefairing assembly 10 can be deflected and guided by means of the fairingassembly 10, i.e., by the fairing 36 and 38 in a particularlyadvantageous manner.

FIG. 6 shows a cross sectional profile 58 of the forward fairing 36 indetail. At most elevations, the cross sectional profile 58 of theforward fairing 36 being a center panel begins at or slightly inboard ofan outer tire tread edge 60 of the tire 30 of the wheel 26 and thenprogresses outwards until just outboard of the tire wall. The crosssectional profile 58 is generally cubic with some deviation for stylingpurposes. The resulting shape “shingling” effectively intercepts airflowfrom penetrating the leading tire gap and diverts it outboard and aroundthe trailing tire gap and rear tire with minimal disruption continuity.

FIG. 7 shows a cross sectional profile 62 of the fairing 38 being an aftpanel. At any elevation, the cross sectional profile 62 of the aft panelbegins at or slightly inboard of an outer tire tread edge 64 of the tire30 of the wheel 28 and grows progressively outward until ending abruptlysome distance outboard of the tire wall. The cross sectional profile 62is generally quadratic with some deviation for styling purposes. Theresulting air ramp gives outward momentum to the air stream whichprevents some inboard flow from interacting with aero-disruptivefeatures on the trailer. Thus, the fairing assembly 10 controlsaerodynamic flow near the wheels 26 and 28 of the tractor pulling thetrailer. The fairing assembly 10 serves to decrease anti-motiveaerodynamic forces in close proximity to the wheels 26 and 28 and alsocondition the flow for better performance downstream around shapes andfeatures of the trailer. The surface shapes and features of the fairingassembly 10 can improve the marginal performance with respect toaerodynamics by more than 50%. FIG. 5 shows a sectional view of thefairing assembly 10 along a cut line B-B shown in FIG. 1. As can be seenfrom FIG. 5, the forward fairing 36 is arranged between the drive wheels26 and 28 and extends at least substantially angularly to thelongitudinal direction of the vehicle.

The cross sectional profile 62 of the aft panel (fairing 38) is arrangedin a plane of the longitudinal direction of the vehicle and thetransverse direction of the vehicle, the plane being also referred to asXY-plane.

FIG. 8 shows a cross sectional profile 66 of the rear fairing 38 in aplane of the transverse direction of the vehicle and the verticaldirection of the vehicle, the plane being also referred to as YZ-plane.At any longitudinal position, the cross sectional profile 66 of thefairing 38 is concave, wherein a width of the fairing 38 is indicated byw. This is intended to reduce flow diversions which helps to sustain theoutward momentum of the air flow compelled by the air ramp formed by thecross sectional profile 62.

As can be seen from FIGS. 1 to 8, the fairing assembly 10 is used for atandem axle and thus a dual drive wheel configuration. Alternatively,the panels (fairings 36 and 38) may be positioned relative to a singledrive wheel configuration, i.e., wide based tires.

As can be seen from the figures, the shape of the fairing 36 isoptimized for aerodynamics. The outboard horizontal surface lines of thefairing 36 begin at distance inboard of the tire tread and include anobvious kickout feature which more effectively captures air deflectingoff the back edge of the tire 30 and diverts it outboard and around therear tire. Furthermore, the aft panel (fairing 38) uses a kickoutfeature in an effort to divert flow that would normally flow towards andaround a trailer landing gear and other non-aerodynamic features of thetrailer. The outboard vertical surface lines of the aft panel aregenerally concave. The resulting air stream is convergent and speedingup. In theory, and seemingly in practice, the air moves further down thetrailer before eventually reconnecting with the non-aerodynamic featuresor surfaces of the trailer. Thus, particularly advantageous aerodynamicsof the commercial vehicle can be realized so that the commercial vehiclecan be driven particularly efficiently.

What is claimed is:
 1. A fairing assembly for a commercial vehicle,comprising: a forward fairing configured to be disposed such that theforward fairing begins inboard of an outer tire tread edge of a tire ofa forward drive wheel and progresses outwards to end outboard of a wallof the tire of the forward drive wheel with respect to a longitudinaldirection of the commercial vehicle; and a rear fairing configured to bedisposed such that the rear fairing begins inboard of an outer tiretread edge of a tire of a rear drive wheel and progresses outwards toend outboard of a wall of the tire of the rear drive wheel with respectto the longitudinal direction of the commercial vehicle, wherein therear fairing has a concave cross-section in a transverse direction ofthe commercial vehicle.
 2. The fairing assembly according to claim 1,wherein the forward fairing and the rear fairing each include arespective first portion made of a first material and a respectivesecond portion adjoining the first portion and wherein the secondportion is made of a second material that is different from the firstmaterial.
 3. The fairing assembly according to claim 2, wherein thefirst material is a first plastic material.
 4. The fairing assemblyaccording to claim 3, wherein the first plastic material is athermoplastic elastomer based on olefin.
 5. The fairing assemblyaccording to claim 2, wherein the second material is a second plasticmaterial.
 6. The fairing assembly according to claim 5, wherein thesecond plastic material is an Ethylene-Propylene-Dien-Monomer rubber. 7.The fairing assembly according to claim 2, wherein the respective firstportion has a higher rigidity than the respective second portion.
 8. Thefairing assembly according to claim 2, wherein the respective secondportion forms a respective edge region of the respective fairing.
 9. Thefairing assembly according to claim 1, wherein a cross-sectional profileof the forward fairing is cubic.
 10. The fairing assembly according toclaim 1, wherein a cross-sectional profile of the rear fairing isquadratic.
 11. A commercial vehicle, comprising: an axle; and a fairingassembly according to claim
 1. 12. The commercial vehicle according toclaim 11, wherein the commercial vehicle is a tractor.